Experimental Determination of Delimbing Forces and Deformations in Hardwood Harvesting

Delimbing is the process used to cut the branches off the trunk during tree processing by forest harvester. This process can be described as chipless cutting of green wood at a feed speed of 3 to 7 ms-1.This work aims to identify the parameters influencing the efficiency of the delimbing process. To this end, the main parameters are defined, and different experimental tests are presented. The first experiment was conducted using a dynamometric pendulum that can reach cutting speeds of 10 ms-1. A Digital Image Correlation method was used in order to compute the deformation field in the branch. The deformation fields observed are consistent with previous studies in the literature. The second experimental device was a slow speed test bench. It uses a hydraulic actuator to translate the knife through the branch while measuring force and displacement. Tests were conducted, varying the diameter of branches, to analyze its effect on the cutting force. Proportionality between branch area and cutting forces were verified, and empirical coefficients were obtained for both speeds

Démarche de conception d'une cellule de parachèvement

La fonderie d'aluminium de précision par moules en sable permet de réaliser des pièces complexes de grandes dimensions et de haute technicité. Cependant les exigences industrielles en terme de sécurité et de rentabilité remettent fortement en cause la réalisation manuelle des opérations de parachèvement. Cet article décrit tout d'abord la formalisation des différentes contraintes du process de parachèvement. Nous présentons ensuite différents aspects de la démarche de conception, analyse géométrique, étude d'accessibilité, précision, rigidité, qui a abouti à la définition d'une cellule robotisée 8 axes. Les travaux actuels portent sur la gestion optimisée de la redondance cinématique afin d'améliorer le comportement global de la cellule. Celle-ci est aujourd'hui opérationnelle et l'optimisation est en cours de validation sur des pièces industrielles. Ces travaux sont réalisés en partenariat avec la Société des Fonderies d'Ussel du groupe Alcan, spécialisée dans la réalisation de pièces de haute technicité pour les secteurs aéronautiques, transport et énergie

Modelling of the hardwood harvesting process: feeding model

L'objectif des travaux présentés concerne la modélisation des procédés de bûcheronnage actuels et en cours de développement dans le cadre du projet ECOMEF (Éco-concevoir un outil de mécanisation pour le bûcheronnage dans les peuplements feuillus), et ce en vue d'évaluer et d'optimiser les performances (gain de productivité, mais également efficacité énergétique) des nouvelles solutions envisagées au regard des systèmes existants. Après une présentation du cadre de travail, cette publication présente, dans une première partie, une démarche de décomposition fonctionnelle basée sur la méthode SADT, en vue de déterminer des « briques élémentaires » de modélisation des systèmes d'abattage existants. Ainsi, l'objectif général « Modéliser le fonctionnement d'une tête d'abattage» (considéré comme la fonction A-0 de notre diagramme SADT) a été décomposé en quatre fonctions, très proches des phases de travail des machines actuelles, à savoir modéliser le serrage, l'entraînement, l'ébranchage, et le billonnage du tronc. Au vu de cette décomposition et des priorités formalisées au sein du projet, trois modèles ont été identifiés comme indispensables à développer : un modèle d'entraînement du tronc, un modèle de coupe adapté à l'ébranchage par choc ainsi qu'un modèle de contact entre le tronc et les différentes parties de la tête d'abattage. Dans une seconde partie, le modèle d'entraînement est détaillé : les études existantes ainsi que les objectifs de ce modèle sont présentés. Afin de développer chaque modèle, deux démarches sont menées simultanément : le développement d'une approche analytique et la mise en place de campagnes d'essais expérimentaux en vue du recalage et/ou de la caractérisation des modèles. L'approche théorique mise en place pour le modèle d'entraînement est détaillée, et enfin le développement d'un banc d'essai et les expérimentations prévues pour le recalage du modèle sont évoqués, avant de conclure sur les résultats attendus

Congenital ichtyosis – a clinical research

Generalităţi. Ihtiozele ereditare reprezintă un grup heterogen de manifestări descuamative cutanate, cum ar fi ihtioza vulgară şi ihtioza X-lincată, sunt cele mai frecvente. Material şi metode. Au fost analizate fişele de observaţie clinică (111 cazuri) ale pacienţilor cu ihtioze ereditare, trataţi în perioada 1986-2015, în ale cadrul Spitalului Dermatologie şi Maladii Comunicabile. Rezultate. Vârsta pacienţilor a oscilat între 1-18 ani (m/f –42/69; rural/urban – 87/24). Spectrul nosologic depistat s-a prezentat în felul următor: ihtioză vulgară – 76 (68,5%) cazuri; eritrodermia ihtioziformă non-buloasă Brocq – 23 (20,7%) cazuri; eritrodermia ihtioziformă buloasă Brocq – 3 (2,7%) cazuri; ihtioza X-lincată – 7 (6,3%) cazuri; sindromul Netherton – 2 (1,8%) cazuri. Aşadar, transmiterea autosomal-dominantă s-a constatat în 79 (71,2%) cazuri, autosomal-recesivă – în 25 (22,5%) cazuri şi X-lincată – în 7 (6,3%) cazuri. Toţi bolnavii prezentau în antecedente pusee repetate de amigdalită, bronşită, pneumonie, infecţii virale acute, piodermie, anemie. Întârzierea dezvoltării somatice şi intelectuale s-a consemnat în 32 (28,8%) cazuri. Au fost evidenţiate următoarele forme clinice de ihtioză vulgară, care aveau o evoluţie benignă: forma simplex – 70 de cazuri; xerodermia şi forma nigricans – câte 3 cazuri. Debutul maladiei a avut loc între 2 şi 12 luni de viaţă, constatându-se în 53 (69,7%) cazuri, între 1-4 ani – în 17 (22,3%) cazuri şi peste 4 ani – 6 (8%) cazuri. Tabloul clinic prezenta, în marea majoritate a cazurilor, o descuamaţie predominantă pe părţile de extensie ale membrelor, mai puţin pe trunchi, faţă, scalp, cu scuame fi ne, albicioase, excepţie fi ind forma nigricans. Manifestările descuamative de ihtioză au fost completate cu hiperkeratoză caloasă a coatelor şi genunchilor, keratoză pilară, accentuarea pliurilor palmare şi plantare în 51 (67,1%) cazuri. Ihtioza X-lincată a fost caracterizată prin debut în primele 6 luni de viaţă, o evoluţie benignă, scuame mari poligonale, absenţă keratozei pilare şi a atingerilor palmoplantare. Debutul formelor eritrodermice de ihtioză (eritrodermia ihtioziformă non-buloasă recesivă, eritrodermia ihtioziformă buloasă dominantă) s-a constatat la naştere, având un aspect de „bebe collodion” în majoritatea cazurilor, cu ameliorare în 10-14 zile. O evoluţie gravă, cu afectarea cutanată ulterioară generalizată, s-a observat în 18 (69,2%) cazuri, asociindu-se cu onicodistrofi i şi distrofi i pilare, în jumătate din cazuri. De menţionat o evoluţie extrem de severă la 3 pacienţi cu eritrodermie ihtioziformă buloasă, debutând în primele zile de viaţă, cu bule şi decolări epidermice. Aspectul clinic ulterior prezenta scuame groase, verucoase, gri-brune, acoperind suprafaţa cutanată eritematoasă, keratodermie palmo-plantară, onicodistrofi i, alopecie, suprainfecţii cutanate. Debutul sindromului Netherton s-a constatat în primele 3-4 luni de viaţă, manifestările clinice cutanate fiind prezente în 3 aspecte: ihtioza liniară circumfl exă Comel, manifestări atopice şi distrofii pilare (hipotrihoză, trichorrhexis invaginata). Tratamentul ihtiozelor a inclus preparate topice cu uree, acid salicilic, emoliente, vitamina A, având un efect curativ bun la bolnavii cu ihtioză vulgară (xerodermie simplă) şi o ameliorare neînsemnată, temporară, în celelalte forme studiate. Concluzii. Profilul ihtiozelor constată predominarea sexului feminin, precum şi a formelor clinice de ihtioze dominante cu evoluţie benignă şi răspuns bun la tratament, excepţie fiind eritrodermia ihtioziformă buloasă Brocq. De menţionat, gravitatea şi rezistenţa la tratament a formelor recesive de ihtioză. Din punct de vedere profilactic, sfatul genetic reprezintă singura posibilitate de a efectua diagnosticul antenatal.Overview. Congenital ichtyosis represents a heterogenous group of desquamative skin disorders among which the most frequent are ichtysosis vulgaris and X-linkate ichtyosis. Material. 111 medical fi les of patients with congenital ichtysosis, who have been treated at the Hospital of Dermatology and Communicable Diaseases during 1986-2015, were included in the reasearch. Results. Patients’ age has oscillated from 1 till 18 years old (m/f-42/69; rural/urban – 87/24). Range of clinical forms included, as follows: ichtyosis vulgaris – 76 (68.5%) cases; non-bulous ichtyoziform erythroderma – 23 (20.7%) cases; bullous ichtyoziform erythroderma of Brocq – 3 (2.7%) cases; X-linkate ichtyosis – 7 (6.3%) cases; Netherton syndrome – 2 (1.8%) cases. Th us, autosomal-dominant transmission of the disease was established in 79 (71.2%) cases, as well as autosomal-recessive was present in 25 (22.5%) cases and X-linkate in 7 (6.3%) cases. All patients prior have developed recurrent episodes of amigdalitis, bronchitis, pneumonia, acute viral infections, pyodermas and anemia. Both, somatic and mental retardation, were seen in 32 (28.8%) cases. Benign forms of ichtyosis vulgaris were described as follows: simple form in 70 cases; xeroderma and nigricans form 3 cases of each. Onset of the disease between 2 and 12 months old was observed in 53 (69.7%) cases, from 1 till 4 years old in 17 (22.3%) cases and aft er 4 years in 6 (8%) cases. In majority of cases, a desquamation with fi ne white scales on extensor surface of limbs, less on trunk, face and scalp of the patients were seen; nigricans form was an exception. Also, a massive hyperkeratotic depositions on patients’ elbows and knees were present, as well as follicular hyperkeratosis with accentuated skin markings on palms and soles were observed in 51 (67.1%) cases. Cases of X-linkate ichtyosis have been chracterized by an early onset within fi rst 6 months of patients’ life, a benign evolution of the disease, large polygonal scales, absence of follicular hyperkeratosis and involvement of palms and soles. Onset of ichtyosiform erythroderma (recessive non-bullous and dominant bullous forms) was described at delivery with “collodion bebe” manifesations, as well as benign evolution, in majority of cases, on the 10-14th days of life. A severe progression of the disease with generalized skin involvement was seen in 18 (69.2%) cases, associated with onichodystrophy and trichodistrophy in a half of cases. It is important to notice an extreme severe evolution of bullous ichtyosiform erythroderma in 3 children with early onset, bulla and wide exfoliation of the epidermis. Late clinical manifestations were presented by multilayered, verrucose, gray-brown scales, which covered a generalized erythema; palmo-plantar keratoderma, onicodystrophy, alopecia and pyodermas were seen as well. Development of Netherton syndrome was established in the fi rst 3-4 months of patients’ life. Clinical aspects included as follows: liniar ichtyosis Comel, atopic eczema and trichodystrophy (hypotrichosis and trichorrhexis invaginata). Topical treatment has involved remedies with urea, salicylic acid, emolients and vitamin A with a good eff ect in patients with ichtyosis vulgaris (xeroderma, simple form) and a temporary benefi c result in other forms. Conclusions. Ichtyosis occurs mostly in females; prevalence of dominant forms with a benign evolution and positive response to topical treatment were observed; only bullous ichtyosiform erythroderma of Brocq made an exception. Ressecive forms of ichtyosis were marked by severe evolution and treatment resistance. Consultation of a genetic specialist repersents a unique solution for antenatal prohylaxis of the disease

Pemfigusuri autoimune (profunde şi superficiale): protocol clinic naţional PCN-239

USMF „Nicolae Testemiţanu”, IMSP SD și MCAcest protocol a fost elaborat de grupul de lucru al Ministerului Sănătăţii al RM, constituit din reprezentanţii Catedrei Dermatovenerologie a Universităţii de Stat de Medicină şi Farmacie „Nicolae Testemiţanu”. Protocolul naţional este elaborat în conformitate cu ghidurile internaţionale actuale privind pemfigusul şi va servi drept bază pentru elaborarea protocoalelor instituţionale, în baza posibilităţilor reale ale fiecărei instituţii în anul curent. La recomandarea MS pentru monitorizarea protocoalelor instituţionale pot fi folosite formulare suplimentare, care nu sunt incluse în protocolul clinic naţional

Structural synthesis of parallel robots

This book represents the fifth part of a larger work dedicated to the structural synthesis of parallel robots. The originality of this work resides in the fact that it combines new formulae for mobility, connectivity, redundancy and overconstraints with evolutionary morphology in a unified structural synthesis approach that yields interesting and innovative solutions for parallel robotic manipulators.  This is the first book on robotics that presents solutions for coupled, decoupled, uncoupled, fully-isotropic and maximally regular robotic manipulators with Schönflies motions systematically generated by using the structural synthesis approach proposed in Part 1.  Overconstrained non-redundant/overactuated/redundantly actuated solutions with simple/complex limbs are proposed. Many solutions are presented here for the first time in the literature. The author had to make a difficult and challenging choice between protecting these solutions through patents and releasing them directly into the public domain. The second option was adopted by publishing them in various recent scientific publications and above all in this book. In this way, the author hopes to contribute to a rapid and widespread implementation of these solutions in future industrial products

Techniques de conception assistée par ordinateur (CAO) pour la caractérisation de l'espace de travail de robots manipulateurs parallèles

Les environnements CAO fournissent des outils puissants pour la programmation graphique et la manipulation d entités géométriques complexes. Dans cette thèse, nous proposons d exploiter ce potentiel dans le domaine de la conception de robots parallèles. Ces robots sont considérés comme une alternative intéressante vis-à-vis de leurs homologues sériels dans différentes applications comme le pick and place et l usinage. Cependant, leur utilisation industrielle est encore restreinte en raison d un espace de travail limité, de modèles géométriques difficiles à résoudre et l existence de configurations singulières délimitant leur domaine d exploitation. L analyse et la caractérisation de l espace de travail jouent alors un rôle fondamental dans la phase de conception de robots manipulateurs parallèles. Dans ce travail de thèse, nous proposons des approches géométriques originales donnant lieu à un ensemble de méthodes et techniques basées CAO pour l analyse et la caractérisation de l espace de travail de robots parallèles plans et spatiaux. L espace de travail est généré comme un solide dans l environnement CAO à partir d un paramétrage géométrique, d esquisses et d opérations élémentaires telles que le balayage hélicoïdal et l intersection. Nous avons montré que ces méthodes constituent des outils pertinents et efficaces d aide à la conception des mécanismes parallèles. Ils permettent également la résolution du problème géométrique direct et la génération de trajectoires libres de singularités. Plusieurs types de manipulateurs ont été considérés dans ce travail pour mettre en avant et illustrer les techniques CAO / Géométriques proposées : robots parallèles plans à 3 degrés de mobilité de type 3-RPR, 3-RRR, 3-PPR et 3-PRR, robots parallèles spatiaux à 6 degrés de mobilité de type ou 3-CRS ou 3-PRRS.CAD environments provide very powerful tools for graphical programming and manipulation of complex geometric entities. In this thesis, we propose to exploit such potential in the design of parallel robots. These robots are considered an attractive and important alternative towards their serials counterparts in various applications, like pick and place and machining. However, their industrial applications are restricted due to limited workspace, complexity related to resolution of the direct geometric model, and in addition the existence of the singular configurations which bound their application field. The analysis and the characterization of the workspace therefore play an essential role in the design phase of parallel robotic manipulators. In this thesis, we suggest original geometric approaches giving rise to a set of methodologies and techniques based on the use of CAD in order to analyze and characterize the workspace of planar and spatial parallel robotic manipulators. Workspace is generated as a solid in CAD environment by using a parametric geometric model, sketches, and elementary operations such as helical scanning and performing then Boolean intersection operation. We have shown in this thesis, that the proposed methodologies represent relevant and efficient tools which assist designers of parallel mechanisms. Moreover, they allow us to solve the direct geometric problem and to plan singularity-free trajectories. Several types of robotic manipulators have been considered in this work to highlight and illustrate the proposed CAD / Geometric techniques : planar parallel manipulators having three degree of freedom such as 3-RPR, 3-RRR, 3-PPR, and 3-PRR, and spatial parallel robotic manipulators having six degree of freedom 3-CRS-type.CLERMONT FD-Bib.électronique (631139902) / SudocSudocFranceF

Contribution au choix de stratégies d'usinage (application à la finition des pièces de formes complexes)

CLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocCACHAN-ENS (940162301) / SudocSudocFranceF

Eco-innovation dans le domaine des technologies d'épandage (cas de l'épandeur PROLOG)

Ce travail de thèse s inscrit dans la problématique générale du projet ECODEFI - ECOconception et Développement de méthodologies de Fabrication Innovante de machines d épandage financé par l Agence Nationale de la Recherche (ANR) dans le cadre du PRogramme ECOtechnologies et Développement Durable (PRECODD). Le projet ECODEFI porte sur l écoconception et l éco-innovation appliquées aux technologies de l épandage, pour répondre à deux enjeux majeurs : (i) le recyclage des effluents organiques issus de l industrie et de l épuration des eaux et (ii) réduire à la source les risques de pollution des agro-écosystèmes. Face au besoin de prise en compte de l environnement dans le développement des machines d épandage, nous avons proposé une démarche d éco-innovation qui permet d aboutir à des véritables percées technologiques. Cette approche présente une synergie entre l Analyse du Cycle de Vie (ACV), la matrice de non-qualité, la Théorie de Résolution des Problèmes Inventifs (TRIZ), l analyse morphologique et le Processus d Analyse Hiérarchique (Analytical Hierarchy Process AHP). Dans l enchaînement de ces outils, l ACV évalue les impacts environnementaux générés par le système. Puis, pour une meilleure prise en considération des aspects écologiques, nous avons développé un nouvel outil, la matrice de non-qualité, qui définit, à partir des résultats de l ACV, le problème à résoudre en priorité du point de vue environnemental. La méthode TRIZ permet la génération de nouveaux concepts et la résolution des contradictions. Ensuite, l analyse morphologique offre la possibilité d étendre l espace de recherche des solutions d un problème de conception de manière systématique. Enfin l AHP identifie la ou les solution(s) prometteuse(s) en fournissant une logique claire pour les choix réalisés. Dans notre étude, nous nous sommes principalement intéressés aux problèmes rencontrés sur la machine PROLOG lors de la phase d épandage des produits compostés. En effet, l'épandage du compost se développe fortement et l'entreprise SIRTEC souhaite pouvoir réaliser cette tâche avec leurs machines conçues initialement pour des matériaux granulaires. L approche a été appliquée pour résoudre le problème d extraction de ces produits suite à la formation de voûtes à l intérieur de la trémie de l épandeur.This thesis is part of the ECODEFI project (ECOconception et DEveloppement de méthodologies de Fabrication Innovante de machines d épandage Ecodesign and development of innovative production methods of spreading machines) funded by the French National Research Agency within the framework of Eco-technologies and sustainable development programme (PRECODD) The ECODEFI project focuses on ecodesign and eco-innovation applied to spreading technologies, to address two major issues : (i) recycling of organic waste from industry and sewage and (ii) reducing the source of pollution risk of agro-ecosystems. Facing the need to take into account the environment in developing spreading machines, we proposed an eco-innovation design approach that can lead to real breakthroughs. This approach provides a synergy between the LCA, the non-quality matrix, TRIZ method, the morphological analysis and the AHP. In the sequence of these tools, LCA (Life Cycle Assessment) assesses the environmental impacts generated by the system. Then, for a better consideration of environmental aspects, we developed a new tool, the non-quality matrix, which defines the problem requiring solving first from an environmental point of view, from the LCA results. The TRIZ method allows the generation of new concepts and contradiction resolution. Then, the morphological analysis offers the possibility of extending the search space of solutions of a design problem in a systematic way. Finally, the AHP (Analytical Hierarchy Process) identifies the promising solution(s) by providing a clear logic for the choice made. In our study, we are mainly interested in problems on the PROLOG machine during the phase of composted products application. Indeed, compost application is strongly growing and the SIRTEC Company hopes to accomplish this task with their machines which were initially designed for granular materials. The approach has been applied to solve the problem of extraction of these products due to the formation of arches inside the spreader hopper.CLERMONT FD-Bib.électronique (631139902) / SudocSudocFranceF

Conception, modélisation et planification de mouvements d'un robot de résection pour la neurochirurgie

Depuis son apparition la robotique chirurgicale s avère bénéfique pour les patients et pour les praticiens car elle améliore la qualité des opérations. Ces travaux de thèse portent sur la conception, la modélisation et la planification de mouvements d un système robotique destiné à réséquer une tumeur cérébrale. La définition des contraintes liées à la tâche de résection de tumeur (adaptabilité aux différentes formes de tumeurs et espace de travail restreint et évolutif) met en évidence la problématique liée à la conception du robot et à sa stratégie de résection. La conception modulaire retenue utilise des câbles et dispose de sept degrés de liberté. Une modélisation géométrique de la solution est proposée. La planification de trajectoire du robot redondant dans un environnement dynamique qui dépend de sa trajectoire est basée sur un principe de génération interactive. Elle utilise un découplage des degrés de liberté du robot et définit des procédures élémentaires qui pourront être choisies et assemblées par le neurochirurgien. Une méthode par discrétisation est proposée pour déterminer l espace des procédures adaptées au robot et limiter le choix du chirurgien aux procédures effectivement réalisables. Une simulation montre que la solution robotique associée à la méthode interactive de génération de trajectoire permet de réséquer une grande partie d une tumeur témoin, et la réalisation d un démonstrateur offre des perspectives d expérimentations en conditions simulées.Since the beginning of surgical robotics, surgical robots continue to find their place in clinical routine. They improve the quality and safety of operations, and comfort for the surgeon. This work addresses the design, modeling and path planning of a robotic system for brain tumor resection. The characterization of the surgical task (adaptability to the high diversity of tumor shapes, limited and evolving workspace) points out the requirements for the robot design and resection path planning. A modular robot with seven degrees of freedom is selected (high dexterity) and is actuated by wires. A kinematic (geometric) model is built.Motion planning of the redundant robot in evolving and path depending workspace is based on an interactive path planning. The method uncouples the degrees of freedom and defines elementary procedures, which are assembled in an arbitrary sequence by the neurosurgeon.A discretization method allows computing the procedure space that presents the possible locations, orientations and sizes of resected areas with respect to the robot limitations to bound procedure choices. A simulation on a real tumor case reveals that the chosen robotic concept associated to the interactive motion planning method allows removing the tumor for the most part. A demonstrator is realized and will provide opportunities for experiments in simulated conditions.CLERMONT FD-Bib.électronique (631139902) / SudocSudocFranceF